Trumpeter swan numbers are on the rise in the Interior

Posted: Friday, May 04, 2001

By TIM MOWRYFairbanks Daily News-Miner

FAIRBANKS (AP) -- A trumpeter swam spread its wings in the pond at Creamer's Field Migratory Waterfowl Refuge late last month as its mate sat nearby. They were just one of a dozen pair of trumpeter swans that dwarfed the hundreds of Canada geese that surrounded them in the ponds at Creamer's Field Migratory Waterfowl Refuge this season.

Their huge pearly-white bodies, long, S-curved necks and dark, black beaks made the swans stick out like fleece-wearing tourists in a crowd of Carhartt-clad Alaskans.

Weighing in at between 20 and 30 pounds, trumpeter swans are world's largest species of waterfowl and the heaviest flying bird in the world. They make the Canada geese lounging around Creamer's Field look like midgets.

As he addressed a group of fifth graders as part of the annual Fifth Grade Bird Watch, Alaska Department of Fish and Game biologist Mark Ross acknowledged the unusually high number of swans in the field.

''Last year we didn't have hardly any trumpeter swans and this year we've got record numbers of swans,'' Ross told the children. ''Does anybody know the reason why we might have so many swans this year?''

Ross laughed off the answer. ''Let's not jump to conclusions,'' he told the fifth grader with a smile,and went on to tell the kids the probable reason for the high number of swans this year at Creamer's was the unusually large volume of water covering the field.

While that may be true, Alston also may be right.

Global warming is one of several theories being tossed around to explain what has been a dramatic increase in trumpeter swans in the last 30 years, according to U.S. Fish and Wildlife biologist Bruce Conant in Juneau.

''It takes a while to get trumpeters on wing and any little effect that can extend that season in the spring or the fall would increase chances of young of the year surviving,'' Conant said by phone.

Other theories for what has been a veritable explosion in swan numbers in Alaska -- from 2,847 in 1968 to 17,155 last year -- include an increase in the number of beavers in Alaska, which has produced more trumpeter swan habitat. Trumpeter swans consider equisetum, more commonly called horsetail, as a delicacy and it grows mostly in marshy areas created by beaver ponds.

Another speculation is that wintering trumpeter swans have benefited from a switch in diet by feeding in agricultural fields in British Columbia and Washington because of loss of natural feeding areas as a result of development, logging and pollution.

It also helps that hunting trumpeter swans has been illegal since the early 1900s as a result of the Migratory Bird Treaty Act. The population had been decimated by Lower 48 market hunters and swans were listed as an endangered species.

Whatever the reason, a record number of swans have showed up at Creamer's Field this year, providing Fairbanks waterfowl watchers a rare opportunity to get a close-up look at the largest and arguably prettiest waterfowl species in the world.

''We haven't had very many swans at all since the early 90's when we had those winters with deep snow and had a lot of water,'' said Fish and Game biologist John Wright, refuge manager at Creamer's Field. ''They're beautiful.''

Trumpeter swans are one of the first migratory birds to arrive in Alaska in mid April and one of the last to leave in late September or early October because of the long time it takes young swans, called ''cygnets,'' to fledge. Eggs hatch after about 35 days and it can take 2 1/81/2 3/8 months for cygnets to fly. During early freeze ups, swans have been known to move into streams and rivers to prolong their stay in Alaska. Young swans unable to fly have also been found frozen into water.

Biologists estimate that 80 percent of the world's trumpeter swan population migrates to Alaska each spring and two-thirds of them nest in the Interior. In the last 20 years, the number of swans in Alaska has increased by almost 10,000 and the birds have greatly expanded their nesting territories. In 1980, biologists counted only 15 swans in the upper Tanana Valley near Tok. Last year, they counted 1,582.

Fish and Wildlife Service biologists conduct the statewide trumpeter swan surveys only once every five years and sooner or later the population will peak, Conant said. When that will happen is anybody's guess, though counts in some Southcentral survey areas appear to be leveling off while numbers in the Interior continue to climb.

Trumpeter swans have also been transplanted from Alaska to some states in the Lower 48 such as Minnesota, Wisconsin, Michigan, Ohio and Iowa in an attempt to revive dwindling trumpeter populations Outside. Eggs were collected in Alaska, transported to the Lower 48 and Canada and placed in the nests of wild trumpeter, tundra and mute swans to hatch. Cygnets have also been transported from Alaska to the Lower 48. The program has been extremely successful.

The increase in trumpeter swan numbers has also resulted in heightened awareness.

One of the reasons opponents of an intertie across Tanana Flats cited for building the power line elsewhere was that it would disturb nesting trumpeter swans. The Trumpeter Swan Society, a national organization dedicated to the preservation of the birds, opposed the intertie route chosen by the state in an attempt to protect the Tanana Flats nesting grounds.

Critics of airboats have also used nesting trumpeter swans as a reason to regulate airboat traffic in Tanana Flats during Alaska Board of Game meetings.

The increase in trumpeter swans in some Lower 48 states where tundra swan hunting is legal has also persuaded waterfowl hunters in those states to push for a generic swan hunting season that would allow them to shoot either tundra or trumpeter swans.